The invention relates to a motor-vehicle key for a remote-controlled motor-vehicle locking system. Such a motor-vehicle key is also called an electronic key. A remote-controlled locking system can be a locking system equipped with a mechanically actuatable remote controller as well as a locking system provided with a coil in a so-called xe2x80x9ccheck cardxe2x80x9d or transponder, for example where the locking action is set in operation by actuation of a door handle.
Since the introduction of remotely operable motor-vehicle locking systems the use of the standard mechanical key has been limited as a rule to the occasional circumstances when the remote-control system, for example, does not work because of insufficient power or other reasons. Only under these conditions must one use a mechanical key that actually serves as an emergency key and generally is constructed of materials, e.g. plastic, that are not suitable for the long service life of a standard motor-vehicle key. In addition it has been noted that after years of using a mechanically actuated locking system the user has a tendency to want to do the unlocking by means of a key held in the hand.
In particular a key holder with a owing-out emergency key is known. the emergency key is held in a side pocket of the key holder and is thus relatively easy to access and even see from outside (see German 3,902,537).
Furthermore an electronic remote-control key is known where the key housing has the external shape of a car and the emergency key has a blade inserted into the front or rear of the car-shaped housing. In this case the emergency key in the key housing forms a push rod. The push rod in turn forms the key head or the key grip and projects from the car-shaped housing in order to be directly accessible in case of need and so that it can be pulled out (see German 297 22 484). As a result it is not out of the question that the user out of habit pulls out the thus mounted emergency key to open the car. In addition the projecting key can be a hindrance.
Finally an electronic key is known for use with locking systems in motor vehicles that has a housing on which an additional key blade is provided as emergency key for a mechanical lock. The emergency key is formed as a separate key from the key. The housing has a socket in which the blade of the emergency key fits. With this known embodiment the housing has a grip part for the user and a jack part formed on it while the emergency key has like a standard key a blade and a grip part which projects from the housing. Finally the emergency key does not fit fully into the actual key housing. This is unsatisfactory (see German 4,444,913).
It is an object of the invention to provide a motor-vehicle key for remote-control motor-vehicle locking systems where the emergency key is readily accessible in case of emergency but where it is used just out of habit is impeded. In addition the emergency key intended only for emergency use is to be protected against damage.
In order to attain this object the invention is a motor-vehicle key for a remote-control motor-vehicle latching system having a key housing holding a remote-control circuit and a mechanical emergency key and wherein
the key housing has a cover with a keypad and a split base formed by two base parts
the emergency key has a key head connected with the base the part forming a key grip, and
the other base part has a seat for the key blade
The features of the invention have the effect that the emergency key is wholly contained in the key housing and thus is integrated in the key housing formed as a transmitter housing. In this manner the emergency key is not visible or noticeable from outside so that the vehicle or key user is not going to be inclined to use the emergency key to open the vehicle and in fact such usage is made difficult. Thus the emergency key, if it is for example made of plastic, is not damaged by unnecessary use. In fact the key housing gives no clue to the presence of an emergency key inside the housing which has a standard external design. Mounting the emergency key in the key housing allows the housing to be made as small as possible in that the base part also forms the key head while the other base part forms a seat for the key blade.
Further features are describe in the following. Thus the key blade is releasably retained in the base part. According to a further embodiment of the invention it is also possible for the key blade to be longitudinally slidable in the key-grip forming base part and when fully inserted is operational and releasably retained in the base part. Such a slide interfit of the emergency key allows a further reduction of the length of the key housing and minimizing of its outside dimensions. The invention further proposes that the base be transversely split and the two base parts be snap-fitted together. Preferably the cover and the base are connected together by ultrasonic welding or adhesive bonding. Thus the base part forming the key grip, when the battery needs to be changed, can simply be pulled out of the base part 3 holding the key blade. In addition the cover and the base have an ignition-key stump for starting the car so that when the stump of the key is turned in the ignition the transponder in the housing is read (travel lock). Finally according to the invention the emergency key is mounted underneath the remote-control circuit in the base and the key head presses a battery into electrical contact against a circuit plate of the remote-control circuit when the emergency key is fitted into the key housing. The remote-control circuit has on the circuit plate the standard transmitter and receiver and a controller and integrated transponder for a drive lock, or alternatively is provided with a coil or a transponder for the locking system.